Slack-preventing guide device for knitting machines



M ZWICKY SLACK PREVENTING GUIDE DEVICE FOR KNITTING MACHINES Feb. 5,1929,

Filed Nov. 23, 1927 Melchior Z widgy INVENTOR ATTORNEYS.

Patented Feb, 5, 1929.

UNITED STATES 1,701,169 PATENT OFFICE.

MELCHIOB ZWICKY, OI BERKSHIRE HEIGHTS, PENNSYLVANIA, ASSIGNOR TO TEX-TILE MACHINE WORKS, O1 WYOMISSING, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

SLACK-PREVENTING GUIDE DEVICE FOR KNITTING MACHINES.

. Application filed November as, 1927. Seriallq. 235,318.

This invention relates to a yarn feed mechanism for, knitting machines,and moreparticularly to a thread guide device comprising a frame havingan eyeleted guide eye passing through a thread-supporting shelf uponwhich latter a flat spring normally rests to press upon the passingthread, said spring being raised tofree the thread during feedingmovement of the latter but engaging the same at times to preventslackthereof.

Such devices are in common use and are usual-lyknown as Snappers, and ashereto fore made have been the source of much trou-- ble and annoyancedue to the friction of the thread cutting grooves in their supportingshelf, to the harm of the latter and the thread, and such groovesdestroying propercontact of the spring in its slack preventing pressureon the thread. 1

The object of the present invention is to avoid such harmful threadcutting of the supporting shelf, prolong indefinitely the useful life ofthe device, and do away with the constant need of care and adjustment toinsure desired prevention of slack thread; and, with this end in view,it comprises the im roved construction hereinafter fully descri d inconnection with the accompanying drawings, the novel features of. whichare set" forth in the appended claim.

Fig. 1 shows in plan view a thread, guide device or snapper embodying myimprove: ments, such vlews showing its usual rotated supporting shaftand spring lifting rod.

Fig. 2 is aside elevation corresponding with Fig. 1 but indicating alsothe machine rame support for the rotated shaft and spring lifting rod. I

Thread guide devices or snappers such as v illustrated in the drawings,are particularly applicable to full fashioned knitting machines, aseries of them corresponding with the number of threads in the severalmachine sections, being employed and commonly se- 4 cured to one or moresupporting shafts 5 extending longitudinally of the machine above theknitting sections and usually rotatably heretofore from the knittingmachine cam ployed, as heretofore, and as illustrated in the drawings,comprises a shaft-engaging portion 10, preferably open for lateralplacement and removal on the shaft, and held in flxed position on thelatter by a set screw 11", said por tion. 10 having diverging.extensions 12 and 13, the outer end of the latter forming a-seat towhich one end of a flat spring 14 is secured,

as by screws 15, and the former, 12, having a thread-supporting shelf16upon which the spring 14 rests in flat position and extends therebeyond,covering a thread-guide eye 17 formed in said shelf 16, which eye isangularly disposed to'a thread-guide eye 18 formed in extension 13. Thethread (19 passing through eye 18, over shelf 16, and through eye 17 isheld tosaid shelf by pressure of spring 14, except when the latter islifted by the turning of shaft 5, when the free end of said springcontacts with a fixed rod 20 extending in spaced parallelrelation toshaft 5. The shaft 5 may of course be fixed and the rod 20 moved" tolift the spring. y v The construction thus far described is old and wellknown, but as commonly made, preferably of cast iron for cheapness, ithas inherentdefects causin trouble and annoyance ticularly' where silkor art ficial silk is employed, soon causes a groove to be worn in thesurface of the thread supporting shelf 16 into does not proper] pressupon the same to which the thread sinks so that the spring 14 preventslack; an such groove cutting is not only hurtful to the thread, butwhen out is likely to catch slight harmless thickened portions of thelatter and cause breakage thereof.

To overcome the above inherent defects while continuing ,the' use of thecheaply formed iron castings, the present improvements consist inemploying a porcelain eyelet in thread guide aperture 17 as heretofore,but forming the same of such length as to roject and extend above thesurface of the t read- I supporting shelf 16, so that, the thread 19,when tautened as during its feedin movement, will be lifted free ofcontact with shelf 16 as it is drawn over the upper lip 21 of theextended eyelet, but which when not feeding or slackened, may be pressedagainst such shelf as heretofore; the spring 14 being provided with anenlarged opening or a erture 22 through which the projecting en 21 ofing eyelet provides a smoot not aflect the action of the spring inpressing" the thread against shelf 16, and the thread cannot causecutting of the shelf surface as such thread is not moving when thespring is in slack preventing contact with it. The hard porcelain lip 21of the u wardly proj ectwear-resisting contact for the feeding yarnwhich indefinitel insures against any vwearing contact with the shelf.

From the foregoingdescription it is thought that the nature of theinvention and its operation will be readily understood; and theimprovements, though simple andreadily made, are important as avoidingin a cheap'eflective way the inherent defects of such thread guidedevices or Snappers as heretofore made, while permitting their continuedmanufacture of simple iron castings which is particularly desirable. 7

What I claim is:

In a yarn feed mechanism for knitting machines, a thread-guide devicecomprising a frame having a spring-carrying arm provided with aguide-eye, and athread-supporting shelf having a guide eye with anupward lay projecting eyelet therein; a flat spring tted to said arm,and lhaving its free end apertured for passage of said projecting eyeletand adapted to. normally press the thread into contact with said shelf;and means for raising the free end of said spring to permit free feedingof the eyelet-raised thread.

In testimony whereof I afiix my signature.

MELCHIOR ZWICKY.

